Symbiotic-GI-16: A Study to Learn About the Study Medicine Called PF-08634404 in Combination With Chemotherapy in Gastroesophageal Cancer
A PHASE 2/3 INTERVENTIONAL STUDY OF PF-08634404 IN COMBINATION WITH CHEMOTHERAPY IN TREATMENT-NAÏVE PARTICIPANTS WITH LOCALLY ADVANCED OR METASTATIC GASTRIC, GASTROESOPHAGEAL JUNCTION, OR ESOPHAGEAL ADENOCARCINOMA
- Untreated Advanced or Metastatic Gastric, Gastroesophageal Junction , or Esophageal Adenocarcinoma
- Metastatic Gastric Cancer
- Gastroesophageal Junction Cancer
- Esophageal Adenocarcinoma
At a glance
- Phase
- Phase 2
- Study type
- Interventional
- Sponsor
- Pfizer
- Enrolment target
- 840
- Started
- 14 May 2026
- Main results due
- 15 January 2032
- Study sites
- 100
- Registry updated
- 28 September 2026
Can you take part?
- Aged 18 years and over.
- Open to any sex.
- You need the condition being studied — healthy volunteers are not accepted.
These are the headline rules only. Every study has a longer list, and whether you are eligible is decided by the research team at the site — never by this page.
Read the full eligibility criteria
Inclusion Criteria: * Histological or cytological confirmed gastric, gastroesophageal junction or esophageal adenocarcinoma. * Evidence of locally advanced or metastatic disease. * Eastern Cooperative Oncology Group performance status (ECOG) 0-1 * No prior systemic therapy for advanced or metastatic disease. * Adequate hepatic, liver, and renal function * HER-2 negative status based on local testing * PD-L1 positive status based on local testing Exclusion Criteria: * Participants with known active CNS metastases, including leptomeningeal, brainstem, meningeal, or spinal cord metastases or compression * Clinically significant risk of hemorrhage or fistula * Major surgery or severe trauma within 4 weeks prior to the first dose, or planned major surgery during the study * History of allogeneic organ transplantation and allogeneic hematopoietic stem cell transplantation. * Any Grade ≥3 bleeding/hemorrhage events within 28 days of Cycle 1 Day 1, or prior history of clinically significant bleeding events * Clinically significant cardiovascular disease, or other comorbidities, within 6 months prior to first dose * Participants with active autoimmune diseases requiring systemic treatment within the past 2 years * Evidence of non-infectious or drug-induced interstitial lung disease (ILD) pneumonitis
What this study is about
In the sponsor’s own words, from the registry.
This study is being done to learn more about a new medicine called PF-08634404 and how well it works when given with chemotherapy to people with gastroesophageal cancer that is locally advanced (spread to nearby tissues) or has spread to other parts of the body.
To join the study, participants must meet the following conditions:
Be 18 years or older. Have locally advanced or metastatic gastric, gastroesophageal junction or esophageal adenocarcinoma Be treatment naïve for advanced or metastatic disease Be in good physical condition and have healthy organs based on medical tests.
The study has two parts:
* In the first part, researchers will check how safe the study medicine in combination with chemotherapy is and how well people respond to it. * In the second part, they will compare study medicine plus chemotherapy to another approved treatment (nivolumab plus chemotherapy) to see which works better.
The treatment will be given in repeated time periods called cycles.
Study sites(100)
UCLA Hematology/Oncology - Atascadero
Atascadero, California, United States
Recruiting
UCLA Hematology/Oncology - Burbank
Burbank, California, United States
Recruiting
UCLA Hematology/Oncology - Encino
Encino, California, United States
Recruiting
UCLA Hematology/Oncology - Marina del Rey
Marina del Rey, California, United States
Recruiting
UCLA Hematology/Oncology - Porter Ranch
Porter Ranch, California, United States
Recruiting
UCLA Hematology/Oncology - San Luis Obispo
San Luis Obispo, California, United States
Recruiting
UCLA Hematology/Oncology - Santa Barbara
Santa Barbara, California, United States
Recruiting
UCLA Hematology/Oncology - Santa Monica
Santa Monica, California, United States
Recruiting
Rocky Mountain Cancer Centers, LLP
Aurora, Colorado, United States
Recruiting
Rocky Mountain Cancer Centers, LLP
Boulder, Colorado, United States
Recruiting
Rocky Mountain Cancer Centers, LLP
Centennial, Colorado, United States
Recruiting
Rocky Mountain Cancer Centers, LLP
Colorado Springs, Colorado, United States
Recruiting
Rocky Mountain Cancer Centers, LLP
Colorado Springs, Colorado, United States
Recruiting
Rocky Mountain Cancer Centers, LLP
Denver, Colorado, United States
Recruiting
Rocky Mountain Cancer Centers, LLP
Denver, Colorado, United States
Recruiting
Rocky Mountain Cancer Centers, LLP
Englewood, Colorado, United States
Recruiting
Rocky Mountain Cancer Centers, LLP
Lakewood, Colorado, United States
Recruiting
Rocky Mountain Cancer Centers, LLP
Littleton, Colorado, United States
Recruiting
Rocky Mountain Cancer Centers, LLP
Lone Tree, Colorado, United States
Recruiting
Rocky Mountain Cancer Centers, LLP
Longmont, Colorado, United States
Recruiting
Rocky Mountain Cancer Centers, LLP
Pueblo, Colorado, United States
Recruiting
Rocky Mountain Cancer Centers, LLP
Thornton, Colorado, United States
Recruiting
Florida Cancer Specialists
Daytona Beach, Florida, United States
Not yet recruiting
Florida Cancer Specialists
Fleming Island, Florida, United States
Not yet recruiting
Florida Cancer Specialists
Palm Beach Gardens, Florida, United States
Not yet recruiting
Florida Cancer Specialists
Sebring, Florida, United States
Not yet recruiting
Florida Cancer Specialists
Wellington, Florida, United States
Not yet recruiting
Florida Cancer Specialists
West Palm Beach, Florida, United States
Not yet recruiting
Illinois Cancer Specialists
Arlington Heights, Illinois, United States
Recruiting
Illinois CancerCare - Bloomington
Bloomington, Illinois, United States
Recruiting
Illinois Cancer Specialists
Chicago, Illinois, United States
Recruiting
Illinois CancerCare - Galesburg
Galesburg, Illinois, United States
Recruiting
Illinois Cancer Specialists
Niles, Illinois, United States
Recruiting
Illinois CancerCare-Ottawa-Fox River Cancer Center
Ottawa, Illinois, United States
Recruiting
Illinois CancerCare-Pekin
Pekin, Illinois, United States
Recruiting
Illinois CancerCare, P.C.
Peoria, Illinois, United States
Recruiting
Illinois CancerCare-Peru - Valley Regional Cancer Center
Peru, Illinois, United States
Recruiting
Illinois CancerCare-Washington
Washington, Illinois, United States
Recruiting
Maryland Oncology Hematology, P.A.
Annapolis, Maryland, United States
Recruiting
Maryland Oncology Hematology, P.A.
Bethesda, Maryland, United States
Recruiting
Maryland Oncology Hematology, P.A.
Brandywine, Maryland, United States
Recruiting
Maryland Oncology Hematology, P.A.
Columbia, Maryland, United States
Recruiting
Maryland Oncology Hematology, P.A.
Germantown, Maryland, United States
Recruiting
Maryland Oncology Hematology, P.A.
Largo, Maryland, United States
Recruiting
Maryland Oncology Hematology, P.A.
Rockville, Maryland, United States
Recruiting
Maryland Oncology Hematology, P.A.
Silver Spring, Maryland, United States
Recruiting
Renown Health Medical Oncology
Reno, Nevada, United States
Recruiting
Renown Office of Clinical Research
Reno, Nevada, United States
Recruiting
Renown Regional Medical Center
Reno, Nevada, United States
Recruiting
Atlantic Health System
Morristown, New Jersey, United States
Not yet recruiting
Atlantic Health System / Overlook Medical Center
Summit, New Jersey, United States
Not yet recruiting
Memorial Sloan Kettering Cancer Center Pharmacy (IMP ship to address)
Long Island City, New York, United States
Recruiting
Memorial Sloan Kettering Cancer Center Pharmacy (IMP storage location)
Long Island City, New York, United States
Recruiting
Memorial Sloan Kettering Cancer Center - David H. Koch Center for Cancer Care (74th Street).
New York, New York, United States
Recruiting
Rockefeller Outpatient Pavilion (53rd Street)
New York, New York, United States
Recruiting
Memorial Sloan Kettering Cancer Center - Main Campus
New York, New York, United States
Recruiting
Oncology Hematology Care Clinical Trials, LLC
Cincinnati, Ohio, United States
Recruiting
Oncology Hematology Care Clinical Trials, LLC
Cincinnati, Ohio, United States
Recruiting
Oncology Hematology Care Clinical Trials, LLC
Cincinnati, Ohio, United States
Recruiting
Oncology Hematology Care Clinical Trials, LLC
Fairfield, Ohio, United States
Recruiting
Showing 60 of 100 sites — filter to narrow it down. 88 of the 100 sites on this study are recruiting right now — a site can stop enrolling while the study as a whole is still open.
Source: ClinicalTrials.gov record NCT07392892. Trialion does not run this study, is not paid to refer anyone to it, and cannot enrol you. Eligibility is always decided by the research team at the site.
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